Study on coupling mechanism of flow-heat transfer-chemical reactions and zonal optimization strategy in reformer

Abstract

To establish guiding principles for reformer structural design and develop corresponding design methodologies, it is essential to investigate the coupling mechanisms among flow, heat transfer, mass transfer, and chemical reactions within reformers under key parameters. Accordingly, a coupled flow-heat transfer model incorporating chemical reactions was developed and experimentally validated. Subsequently, the influence of operational parameters on reforming performance was systematically analyzed. Comparative studies indicate that optimal performance-characterized by high conversion rates and hydrogen production-is achieved at a flow rate of 15 mL/min, steam-to-carbon ratio (S/C) of 1.4–1.7, and wall temperature of 500 K. Analysis of intra-reformer coupling characteristics reveals distinct zoning in the axial growth rate of the Damköhler number (Da), which reflects the temporal distribution of flow and reaction processes. Based on this finding, the reformer channel was partitioned into three optimization zones, and tailored regulation strategies were developed for each zone. Furthermore, analysis of the Da and Lewis (Le) numbers reveals that while a high Da number remains critical for achieving superior conversion rates, optimal conversion efficiency can be attained when elevated mass diffusion rates are coupled with moderated thermal diffusion, corresponding to Le numbers in the range of 0.5–1.